JPH04248785A - Rate variable type video coding transmission method and rate variable type video coding transmitter - Google Patents

Abstract

PURPOSE:To reduce information quantity sent in response to a revision instruction of a coded parameter from a video decoder at a receiver side with respect to a rate variable type video coding transmission method and a rate variable type video coding transmitter able to revise share of bands to each video when a coding rate is revised to send plural videos. CONSTITUTION:A decoder side revises the setting of a coded parameter in the video coding transmission method coding video information and sending it in response to a prescribed coded parameter, the revised coded parameter control information is subject to packet processing and sent to a coder and an area displaying coded parameter control information is provided to a packet sent from the decoder to the coder and the coder revises the setting of the coded parameter in response to the coded parameter control information noticed from the decoder to control transmission information quantity.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a video encoding transmission method and a video encoding transmission device used in a high-speed wideband transmission system suitable for video transmission, in which a plurality of videos are transmitted by changing the encoding rate. The present invention relates to a variable rate video encoding/transmission method and a variable rate video encoding/transmission device that enable changing the bandwidth allocation for each video.

[0002] CCITT's I
There is an asynchronous transfer mode (ATM) using broadband ISDN recommended in the series, which divides information into cells (a type of packet) and transmits them. One cell is divided into a header that indicates the cell's destination and route, and an information field that contains user information. The feature of this method is that since the user terminal can transmit only significant information in a cell, the transmission path can be used more effectively by not transmitting unnecessary information.

0003

2. Description of the Related Art In conventional video transmission, quantization step width, video area, scale, and other encoding parameters are determined in advance between a video encoding device and a video decoding device. Therefore, it has not been possible to unilaterally change these encoding parameters in accordance with a request from a video encoding device on the transmitting side or a video decoding device on the receiving side.

On the other hand, when changing encoding parameters such as video area and scale, the video signal from the video encoding device is fixed, and the video area and scale displayed by the video decoding device on the receiving side are changed. Was.

[0005]

[Problem to be Solved by the Invention] As described above, since it is not possible to manipulate the amount of information to be transmitted in conventional video encoding and transmission devices (video encoding devices and video decoding devices), it is not possible to change the encoding parameters. Even if the amount of information decreased, the amount of information transmitted did not change, and there was a limit to the effective use of the transmission path.

The present invention provides a variable rate video encoding and transmission method that can reduce the amount of information transmitted in response to an instruction to change encoding parameters issued from a video decoding device on the receiving side, and a variable rate video encoding method. It is characterized by being equipped with an encoding transmission device.

[0007]

[Means for Solving the Problems] A variable rate video encoding device according to claim 1 includes encoding means for encoding video information converted into digital information according to predetermined encoding parameters; A video encoding device comprising a transmitting means for packetizing and transmitting encoded video information,
The method further comprises receiving means for processing a received packet, extracting encoding parameter control information and transmitting it to the encoding means, the encoding means changing settings of encoding parameters according to the encoding parameter control information. , is characterized in that it includes a control means for controlling the amount of transmitted information.

The variable rate video decoding device according to claim 2 includes receiving means for processing a received signal transmitted in packets, and decoding video information from the obtained packets according to predetermined encoding parameters. In the video decoding apparatus, the decoding means includes a control means for changing the setting of the encoding parameter according to the encoding parameter control information to be set, and the encoding parameter control information is It is characterized by comprising a transmitting means for packetizing and transmitting information.

[0009] The variable rate video encoding and transmission method according to claim 3 encodes video information according to predetermined encoding parameters, further packetizes it and transmits it, and extracts data from received packets according to the corresponding encoding parameters. In a video encoding transmission method for decoding video information, on the decoding device side, the settings of the encoding parameters are changed, and the changed encoding parameter control information is packetized and transmitted to the encoding device side, The packet transmitted from the decoding device to the encoding device is provided with an area for displaying the encoding parameter control information, and the encoding device side performs encoding according to the encoding parameter control information notified from the decoding device side. It is characterized by changing the settings of parameters to control the amount of information to be transmitted.

[0010] A variable rate video encoding and transmission device according to claim 4 comprises the variable rate video encoding device according to claim 1 and the variable rate video decoding device according to claim 2. The present invention is characterized in that at least one of a quantization step width, a video area, and a video scale is used as the encoding parameter whose settings are to be changed.

[0011]

[Operation] The present invention allows the video encoding device to take in the encoding parameter control information transmitted from the video decoding device via the receiving means, and change the settings of the encoding parameters in the encoding means, thereby reducing the amount of information to be transmitted. can be controlled. On the other hand, the video decoding device performs decoding processing using the encoding parameters notified to the video encoding device. That is, a change in the encoding parameter can be recognized by both the video encoding device and the video decoding device, and the amount of information to be transmitted can be reduced by the change.

0012

Embodiment FIG. 1 is a block diagram showing the configuration of a first embodiment of a video encoding apparatus according to the present invention. In the figure, information on each pixel of the video to be transmitted is converted into a digital value and written into a frame memory 11, compressed via an encoder 12, and further quantized by a quantizer 13 to form a packet. It is input to the assembly circuit 14. The packet assembling circuit 14 packetizes the encoded and quantized video information and sends it to the transmission path.

Here, the feature of the present invention is that in this embodiment, the quantizer 13 has a plurality of quantization tables, and the corresponding quantization table is selected under the control of the quantization table control circuit 15. . On the other hand, it includes a packet decomposition circuit 16 that decomposes packets transmitted from the opposing video decoding device and extracts quantization table control information,
The quantization table control circuit 15 is configured to be controlled according to the quantization table control information extracted by the packet decomposition circuit 16.

That is, the quantization table control circuit 15 selects the quantization table of the quantizer 13 according to the quantization table control information notified from the video decoding device, and changes the quantization step width. Reduce the amount of information transmitted. FIG. 2 is a block diagram showing the configuration of a first embodiment of a video decoding device according to the present invention.

In the figure, a packet disassembly circuit 21 connected to the transmission line separates video information from the received packet and sends it to a dequantizer 22, and the dequantized information is sent to a decoder 23. The values of each pixel are restored and written into the frame memory 24. Note that the video information written in the frame memory 24 is converted into an analog value and displayed as a video on the display device.

Here, the feature of the present invention is that in this embodiment, the dequantization table control information is sent from the dequantization table control circuit 25 to the packet assembling circuit 26, and is packetized and sent to the opposing video encoding device. At the same time, the inverse quantizer 22 is provided with a plurality of inverse quantization tables,
The configuration is such that a corresponding inverse quantization table is selected under the control of the inverse quantization table control circuit 25.

That is, the inverse quantization table control circuit 25
The packet assembling circuit 26 notifies the video encoding device of dequantization table control information according to settings from outside the video decoding device, and changes the quantization step width to reduce the amount of information to be transmitted. let Further, the dequantization table control circuit 25 can perform dequantization corresponding to the video encoding device by selecting the dequantization table of the dequantizer 22 according to the dequantization table control information. .

As described above, in the first embodiment of the video encoding and transmitting device shown in FIGS. 1 and 2, the quantization step width is changed in the video encoding device in response to an instruction from the video decoding device on the receiving side. The transmission rate can be freely changed by reducing the amount of information to be transmitted and by performing corresponding dequantization processing in the video decoding device. Figure 3 shows
FIG. 2 is a block diagram showing the configuration of a second embodiment of a video encoding device according to the present invention.

In the figure, information on each pixel of the video to be transmitted is converted into a digital value and written into a frame memory 31, compressed by an encoder 12, and then quantized by a quantizer 33. Packet assembly circuit 14
is input. The packet assembling circuit 14 packetizes the encoded and quantized video information and sends it to the transmission path.

[0020] Here, the features of this embodiment are as follows:
A packet disassembly circuit 16 extracts video area control information indicating the size (number of vertical and horizontal pixels) of the video to be transmitted by disassembling the packets transmitted from the opposing video decoding device; The configuration includes a read address control circuit 35 that controls the read address of the frame memory 31 according to the video area control information provided.

That is, the read address control circuit 35
In this case, the control information indicating the video area to be transmitted is notified from the video decoding device, and the amount of information to be transmitted can be reduced by converting it into a corresponding pixel address and controlling the readout of the frame memory 31. . FIG. 4 is a block diagram showing the configuration of a second embodiment of the video decoding device according to the present invention.

In the figure, a packet disassembly circuit 21 connected to the transmission line separates video information from the received packet and sends it to a dequantizer 42, and the dequantized information is sent to a decoder 23. The value of each pixel is restored and written into the frame memory 44. Note that the video information written in the frame memory 44 is converted into an analog value and displayed as a video on the display device.

[0023] Here, the features of this embodiment are as follows.
The write address control circuit 45 sends the video area control information to the packet assembly circuit 26, packetizes it, and transmits it to the opposing video encoding device, and the write address control circuit 45 sets the write address of the pixel corresponding to the size of the video. is set in the frame memory 44.

That is, the write address control circuit 45
Notifies the video encoding device of video area control information instructed from outside the video decoding device, controls the size of the video to be transmitted, and reduces the amount of information to be transmitted. Furthermore, by specifying the write address of the frame memory 44, the write address control circuit 45 can perform write processing according to the size of the video corresponding to the video encoding device.

As described above, in the second embodiment of the video encoding and transmitting apparatus shown in FIGS. 3 and 4, the video encoding apparatus changes the video area in response to instructions from the video decoding apparatus, and changes the information to be transmitted. The amount can be decreased and the transmission rate can be changed freely. FIG. 5 is a block diagram showing the configuration of a third embodiment of the video encoding device according to the present invention.

In the figure, the configurations of a frame memory 11, an encoder 12, a quantizer 33, and a packet assembling circuit 14 are the same as in each embodiment shown in FIGS. 1 and 3. Here, the feature of this embodiment is that the frame memory 1
A video scaling circuit 51 is inserted between the encoder 1 and the encoder 12, and a packet decomposing circuit 16 that decomposes packets transmitted from the opposing video decoding device to extract video scaling control information; The configuration includes a video scale control circuit 52 that controls a video scale circuit 51 according to information.

That is, in the video scale control circuit 52, the scale rate of the video to be transmitted is set based on the video scale control information (number of vertical and horizontal pixels) notified from the video decoding device. The video scaling circuit 51 performs subsampling (thinning) of the pixels stored in the frame memory 11 according to this scale rate, and performs interpolation processing if subsampling alone cannot accurately correspond to the set scale rate. conduct,
Reduce the amount of information transmitted.

[0028] The video scale control information specifies the size of the video, and the processing in the video encoding device is as follows:
Since the second embodiment of the video encoding device shown in FIG. 3 is equivalent to the case where the video area is handled, the corresponding video decoding process uses the configuration of the second embodiment of the video decoding device shown in FIG. 4. be able to. In this way, in the third embodiment of the video encoding and transmitting apparatus shown in FIG. By decreasing the transmission rate, the transmission rate can be changed freely.

[0029]

[Effects of the Invention] As explained above, the present invention enables the video encoding device to change the quantization step width, video area, scale, and other encoding parameters based on instructions from the video decoding device. The amount of information to be transmitted can be reduced depending on the encoding parameters. Therefore, for example, when applied to a multimedia transmission system that transmits a plurality of videos, it is possible to freely set or change bandwidth allocation according to the amount of information transmitted between media.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a first embodiment of a video encoding device according to the present invention.

FIG. 2 is a block diagram showing the configuration of a first embodiment of a video decoding device according to the present invention.

FIG. 3 is a block diagram showing the configuration of a second embodiment of the video encoding device according to the present invention.

FIG. 4 is a block diagram showing the configuration of a second embodiment of the video decoding device according to the present invention.

FIG. 5 is a block diagram showing the configuration of a third embodiment of the video encoding device according to the present invention.

[Explanation of symbols]

11 Frame memory 12 Encoder 13 Quantizer 14 Packet assembly circuit 15 Quantization table control circuit 16 Packet disassembly circuit 21 Packet disassembly circuit 22 Inverse quantizer 23 Decoder 24 Frame memory 25 Inverse quantization table control circuit 26 Packet assembly circuit 31 Frame memory 33 Quantizer 35 Read address control circuit 42 Inverse quantizer 44 Frame memory 45 Write address control circuit 51 Video scaling circuit 52 Video scale control circuit

Claims (4)

[Claims] Claim 1: A video code comprising: encoding means for encoding video information converted into digital information according to predetermined encoding parameters; and transmitting means for packetizing and transmitting the encoded video information. The encoding device includes a receiving unit that processes a received packet, extracts encoding parameter control information, and sends it to the encoding unit, and the encoding unit adjusts the encoding parameter according to the encoding parameter control information. 1. A variable rate video encoding device, comprising control means for changing settings and controlling the amount of transmitted information. 2. A video decoding device comprising: receiving means for processing a received signal packetized and transmitted; and decoding means for decoding video information from the obtained packets according to predetermined encoding parameters. In the above, the decoding means includes a control means for changing the setting of the encoding parameter according to the encoding parameter control information to be set, and a transmitting means for packetizing and transmitting the encoding parameter control information. A variable rate video decoding device characterized by: 3. A video encoding and transmission method that encodes video information according to a predetermined encoding parameter, further packetizes it and transmits it, and decodes the video information from the received packet according to the corresponding encoding parameter, comprising: The encoding device side changes the encoding parameter settings, packetizes the changed encoding parameter control information, and transmits it to the encoding device side, and the packets transmitted from the decoding device to the encoding device include An area for displaying the encoding parameter control information is provided, and the encoding device side changes encoding parameter settings according to the encoding parameter control information notified from the decoding device side to control the amount of transmitted information. A variable rate video encoding transmission method characterized by: 4. A variable rate video encoding device according to claim 1 and a variable rate video decoding device according to claim 2, wherein the encoding parameters to be changed include a quantization step width, A variable rate video encoding/transmission device characterized by using at least one of a video area and a video scale.